Abstract

Spurs and grooves on the reefs in the northern gulfs of the Red Sea are generally oriented with their long axes normal to the refracted waves. Therefore, they do not lie normal to the reef front but rather intersect it at an angle. There is no correlation between trend of streams on land and the orientation of the spurs and grooves; karstic activity on exposed reef flat surfaces most probably did not play a role in their formation either. Of the eight studied areas, two show clear abrasion patterns; in all others, the seaward growth of corals, as well as abrasion, controls the development of the spur and groove patterns.